1. Field of the Invention
The present invention relates to a motor and a disk drive apparatus.
2. Description of the Related Art
A disk drive apparatus, such as a hard disk drive, typically has a spindle motor arranged to rotate a disk installed therein. The disk drive apparatus includes the disk, a housing, a stator, an FPC (Flexible Printed Circuit), and so on. The housing includes a cover member, a base portion, and so on.
In recent years, additional reductions in thickness and size have been demanded of disk drive apparatuses. In particular, in order to achieve an additional reduction in thickness of a small-sized disk drive apparatus, a housing or a motor arranged inside the housing itself needs to be made thinner. A common motor includes a rotor hub, a shaft, a stator, a base portion, a bearing, and so on. When the motor is assembled, these members are arranged such that they overlap with one another in an axial direction. In order to achieve a reduction in the thickness of the motor itself, each of these members needs to be made thinner.
Here, in the case of a motor in which a shaft is fixed to a rotor hub, a reduction in thickness of the rotor hub results in shortening of a portion of the rotor hub to which the shaft is fixed. This may result in insufficient fixture of the shaft to the rotor hub. Accordingly, an adhesive in a liquid state is applied to an area where the rotor hub and the shaft are fixed to each other.
The bearing is arranged on a lower side of a lower surface of the rotor hub. In the case where a fluid dynamic bearing is used as the bearing, an external shock or the like may cause lubricating oil to leak out to a space above an upper surface of the rotor hub through the area where the rotor hub and the shaft are fixed to each other. Accordingly, a structure arranged to seal the area where the rotor hub and the shaft are fixed to each other is made necessary to prevent leakage of the lubricating oil.